(1) Field of the Invention
The present invention relates to a liquid crystal display and, more particularly, the present invention relates to a liquid crystal display having substantially improved viewing angle, visibility and motion picture display characteristics.
(2) Description of the Related Art
A liquid crystal display (“LCDs) is a widely used type of flat panel display. The liquid crystal display typically has two display panels on which field generating electrodes, such as pixel electrodes and a common electrode, are disposed, and a liquid crystal layer interposed between the two display panels. In the liquid crystal display, voltages are applied to the field generating electrodes to generate an electric field in the liquid crystal layer, and an alignment of liquid crystal molecules in the liquid crystal layer is determined by the electric field. Accordingly, a polarization of light incident to the liquid crystal layer is controlled to display an image on the liquid crystal display.
A popular type of LCD includes the field generating electrodes disposed on the two display panels, and further includes a thin film transistor (“TFT”) for switching a voltage applied to one of the field generating electrodes.
More particularly, in a twisted nematic (“TN”) mode LCD, for example, when no electric field is applied, the liquid crystal molecules are aligned such that long axes thereof between the two display panels are substantially parallel to surfaces of the two display panels, and are spirally twisted with a predetermined pitch from one panel to the other, thereby forming a twisted structure. Accordingly, the arrangement orientation of the long axes of the liquid crystal molecules is continuously changed. Since the liquid crystal layer in the TN mode LCD has a positive dielectric anisotropy, when the electric field is generated substantially perpendicular to the two display panels, the liquid crystal molecules are aligned substantially parallel to the electric field direction, which is substantially perpendicular to the two display panels.
However, due to refractive anisotropy, the LCD has a disadvantage of a viewing direction dependency. Specifically, color and contrast ratio greatly depend on the viewing direction of the LCD, and a reference viewing angle is narrow. As a result, gray inversion occurs in the LCD. Thus, the LCD has poor lateral visibility as compared with front visibility. More specifically, for example, the LCD displays an image that becomes bright and a color thereof becomes more white color as a viewed portion of the image moves away from the front of the LCD, and, in some cases, a luminance difference between high grays actually vanishes, such that the image cannot be viewed. Moreover, LCDs are increasingly being used for multimedia devices, such that wide-angle viewing of pictures and motion pictures is increased, and, as a result, there is a substantial need for an LCD having advantages that overcome the abovementioned deficiencies and include, for example, improved visibility and viewing angle.